add tests for bp gauge

Author: xuanzhaogao

src/BPGauge.jl

@@ -11,6 +11,8 @@ export bp!, bp_update!
 export absorb!
 export apply_gauge!, gauge!
 
+export chain, square_lattice
+
 include("utils.jl")
 
 # define and construct the network
@@ -19,7 +21,10 @@ include("ansatz.jl")
 # bp on the tensor network ansatz
 include("bp.jl")
 
-# operations about gauging``
+# operations about gauging
 include("gauge.jl")
 
+# simple update
+include("su.jl")
+
 end

src/su.jl

@@ -20,6 +20,14 @@ function square_lattice(mx::Int, my::Int, p::Float64; seed::Int = 1234)
     return g
 end
 
+function chain(n::Int)
+    g = SimpleGraph(n)
+    for i in 1:n-1
+        add_edge!(g, i, i+1)
+    end
+    return g
+end
+
 # codes about constructing the einsum expression
 
 function all_eins(g::SimpleGraph{Int}, count::Int)

src/utils.jl

@@ -24,14 +24,6 @@ using Test
 end
 
 @testset "1d chain" begin
-    function chain(n::Int)
-        g = SimpleGraph(n)
-        for i in 1:n - 1
-            add_edge!(g, i, i + 1)
-        end
-        return g
-    end
-
     g = chain(10)
     for d in [2, 3, 10]
         tn = random_state(g, d_virtual = 3)

test/bp.jl

@@ -2,6 +2,8 @@ using BPGauge
 using Graphs, LinearAlgebra, OMEinsum
 using Test
 
+using BPGauge: square_root
+
 @testset "absorb" begin
     for g in [random_regular_graph(30, 3), BPGauge.square_lattice(10, 10, 0.8)]
         tn = random_state(g, d_virtual = 2)
@@ -62,4 +64,43 @@ end
 
     gauge!(tn, bp_state)
     @test inner_product(tn, adjoint(tn)) ≈ 1.0
+end
+
+@testset "guage mps" begin
+    g = chain(100)
+    tn = random_state(g, d_virtual = 8)
+    normalize_state!(tn)
+    
+    bp_state = BPState(tn)
+    bp_path = BPPath(tn)
+    bp!(bp_state, bp_path, tn, verbose = true, err_bound = 1e-14)
+
+    gauge!(tn, bp_state)
+
+    for i in 1:nv(g) - 2
+        G = tn.gauge_tensors[tn.gauge_tensors_map[(i, i + 1)]]
+        T = tn.site_tensors[i + 1]
+        L = ein"ij, jk, jln, kmn -> lm"(G, G, T, conj(T))
+        @show i, maximum(abs.(L ./ L[1, 1] - I(size(L, 1))))
+    end
+end
+
+
+@testset "Vidal gauge" begin
+    g = chain(100)
+    tn = random_state(g, d_virtual = 8)
+    normalize_state!(tn)
+    
+    bp_state = BPState(tn)
+    bp_path = BPPath(tn)
+    bp!(bp_state, bp_path, tn, err_bound = 1e-14)
+
+    gauge!(tn, bp_state)
+
+    for i in 2:nv(g) - 2
+        G = tn.gauge_tensors[tn.gauge_tensors_map[(i, i + 1)]]
+        T = tn.site_tensors[i + 1]
+        L = ein"ij, jk, jln, kmn -> lm"(G, G, T, conj(T))
+        @test maximum(abs.(L ./ L[1, 1] - I(size(L, 1)))) < 1e-6
+    end
 end